<!DOCTYPE html>
<html class="reftest-wait">
  <!-- Test: if button has a disabled fieldset ancestor, but is in the first
             legend, it is not barred from constraint validation and should be
             affected by :-moz-ui-invalid pseudo-class. -->
  <link rel='stylesheet' type='text/css' href='style.css'>
  <script>
    function onLoadHandler()
    {
      var e = document.getElementById('b');
      e.setCustomValidity('foo');
      document.documentElement.className='';
    }
  </script>
  <body onload="onLoadHandler();">
    <fieldset disabled>
      <legend>
        <button class='invalid' id='b'></button>
      </legend>
    </fieldset>
  </body>
</html>
